Motor vehicle crashes are the major cause of death and injury among adolescents. PRB has developed a program of research, including observational and prospective studies, designed to increase understanding of teen driving risks and reduce crash risks during the early months of licensure. Results from our initial studies indicated that teen risky driving behaviors, traffic violations, and crashes were related to low parental monitoring and lenient driving restrictions, especially during the first month of licensure. Based on these findings, the Checkpoints Program was developed to increase parental management of teen unrestricted driving through the use persuasive communications (PCs) in the forms of newsletters and a model driving agreement. In two small randomized trials, one in Connecticut and one in Maryland, the intervention was demonstrated to increase parent-imposed limits on teen driving through 12-months post-license. Curently, a large randomize trial is under way in Connecticut, where 4,000 parent-teen dyads were recruited as teens obtained learner's permits. Families were randomly assigned to intervention or comparison groups. Intervention families receive the Checkpoints video, newsletters, and driving agreement during the mandatory four-month permit period and follow-up newsletters for the first six months of licensure. Intervention effects are assessed at licensure, and three, six and twelve months post-licensure. The results indicate significant differences on driving limits, risky driving, tickets, and crashes through 12-months post licensure. Current studies are designed to evaluate methods for increasing the effectiveness of parent interventions. Other studies are underway to examine the nature of teen driving risks, including the evaluation of the effects of supervised practice driving, driving experience, teen passengers, and the use of electronic devices on driving performance.